Press guard



Feb. 6,1923. L iM- ffi fifi E. DE MAECKER PRESS GUARD FILED SEPT. 15.1919

NVENTOR. In

774G1 7 M K ATTORNEYS.

Patented Feb. 6, 1%23.

rans EDMOND DE MAECREE, OF IRONDEQUOIT, NEW YORK, ASSIGNOR T0 EASTMAN KODAK COMPANY, OF ROCHESTER, NEVT YORK, A. CORPORATION OF NEW YORK.

PRESS GUARD.

Application filed September To all whom it may concern:

Be it known that I, EDMOND DE MAECKER,

a citizen of the United States of America,

residing at Irondequoit, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Press Guards, of whichthe following is a full, clear, and exact specification.

My present invention relates to nachinery, and more particularly to punch presses or other machines having reciprocating parts intermittently operated under the control of a workman in which there is danger of injury to the hands of the operator in placing the work beneath the operating parts; and it has for its objectto provide a safety guard which will be automaticin its operation and which will eject the workmans hand from the danger Zone before the machine functions; a further object is to provide a device of the character described which will reduce the jar and vibration due to the rapidly moving parts thereby causing less wear upon the safety guard and the clutch which operates the machine; and a still further object is to provide an automatic safety mechanism which will prevent the machine clutch from being tripped through the vibrating parts of the safety guard. thereby reducing accidents caused by machines with the usual type of safety guard. To these and other ends the invention resides in certain improvements and combination of parts such as will be hereinafter described, the novel features being pointed out in the claims following the specification.

In the drawings in which like reference characters designate like parts:

Fig. 1 is a front elevation of a punch press provided with a safety guard with a preferred form of my safety device incor porated therewith.

Fig. 2 is a side elevation of the same ma chine as shown in Fig. 1.

Fig. 3 is a detail showing the operating parts of any safety catch in properrelation, the punch press being omitted for clearncss.

Fig. 1 is a detail section of the spring catch in open position. I

Fig. 5 is a view similar to Fig. 4 only in closed position.

My invention can be applied to punch presses having safety guards of various types, and ,is particula ly well adapted toa 15, 1919. Serial No, 323,963.

machine of the type shown in Patent No. 1,178,168, C. A. MacDonald and M. P. Dougherty, April 1, 1916, such a machine being illustrated in the drawings. in the drawings the press consists of alower frame 0 1 on which there is mounted an upper frame 2 carrying a fly wheel 3 on a shaft 4, a clutch 5, and plunger 6 to which a male die 7 maybe fastened, there being a female die 8 on the work table 9. The clutch 5 is operated through a rod 10 connected to a foot treadle 11 pivoted at 12 to the lower frame 1. and is so arranged that a single depression of the foot lever 11 causes the shaft carrying the plunger 6 to revolve once so that work carried on the tablet) will have an operation performed upon it.

In themachine illustrated a press guard or wing 13, made preferably of celluloid, is attached by rivets or otherwise to an arm 1% which is adjustably fastened to a small casting 15. This casting is bored out so as to revolve freely on a stub shaft 16, fastened to a yoke 17 which in turn is attached to the upper frame 2. In order to revolve the casting 15 upon shaft 16. a. link 18 is pivoted to the casting 19 and to the short arm of a bell crank lever 20, whichin turn is pivoted to yoke 17 bya pin 21. The bell crank lover is connected to the foot lever through the follmving parts: links 22, and 23 attach one end of the bell crank lever 20 to a long A rod 26 connects the foot lever 11 to the long lever arm 24, there being a slidable connecting member 26 adjustable along lever 24 on the upper end of rod 26. A set screw 50 in the top of the connection member 26' is for fastening this part in the desired position on lever 24;. The hearing 51 carried by member 26 is in the form of a slot, so as to allow slight movement of a pin 52 car ried by rod 26 before lever 24 moved. The mechanism above described causes the wing 15, to move from the position shown in full lines to that shown in dashed lines in Fig. 1, before the die 7 descends to die 8, so that an operators band would be thrust to one side before the machine functions. The press also has a second wing guard 27 directly behind guard 13 so that in Fig. 1 it cannot be seen. In Fig. 2 the guard 27 is shown at tached to a rod 28 which is fastened to the yoke 17 in such manner that the ram or plunger 6 in descending causes it to move move-s first will remove the operator-s hand from the danger zone. But if this guard falls. wing 2!, which moves alter guard 13 and much more rapldly Wlll remove the 0perators hand as die 7 descends but b e'fiore it reaches the female die 8. T his second guard moves so rapidly that severe bruises are liable to result, so that guard 13 should be made to function as accurately as possible.

In the past guards as described have worked sati fa torily, redu ng h munh of press guard accidents to a very small proportion of the m mb er occurr ng where.

guards are not employed. They occasionally fail; howe er: and I heae'd sc v e h the cause oi failure is that vexcessive vi ration of the Wing guard causes the parts to neact upon the foot lever and trip the clutch so that he wor nnen will e caugh e per ed r- I s also m ch et e t redu e the shock on the va ous pa in o de th they may wear longer and operate more smoothly, but the main {reason :liormydevice is the pnevention .ol accidents. To accomplish these ends I haue provided a short arm ntteohe test t oi St ng 15., wh ch revol with the casting about stub shaft 16. This arm ,30 is caught in itsopen position (that is when wing 13 is in position shown in' full lines 2 by a pi' us catch on s ing of a base pl e .1 att ched to th y k 17, whic is p vot d e l ch. or 32 hr e r l u 1ing EM normally to; g cam su sl-l a ay from an the ja towa plate .31. When the arm -30 DlOBies rapidly 7 ack from ctuat n oi he guard it so that the other (3' n,

strikes the jaw {32 which yields against the pressure oi spring servingas both a shock absorber ande definite latch, A lever 36 pl voted to firame 2 at 3T normally pressed a spring; {38 gtrorn the position shown in {ull lines Fig. ;3 to position shown ,dil ihed lines in. the same figune, has one end 39 adapted [to pa$S tinder a guide 40 and over the beneled surface ll of jaw ,32. A nod 42 connected ,to the toot lever 11 is held toward the glirarne of the machine by a spring e te te e t tlie no r i p r en cf this red e2 o eurte an er, th towe l, be n adapted o e g ge si e Qt -e s end, 1 6., of leve un relea d by the dew were increme t critv a c e 1Z vhie'li cairneed 2 t de ce 4 rid up on bar 4:6 attached to the upper frame 2. In other words the arm .30 is released when the foot treadle starts its .1novement,-and before the wing '13 is actuated, and then the latch is automat cal y losed ,by e spring 5 Th operation r th omplete m chine s fioillcws; v Assuming the machine is in position ment starts,

Mu e 22 T1118 upshown in Fig. 1 when the operator presses down on the treadle 11, the rod as moving down causes cam li-5 to ride up on bar e6 releasing catch ad from .)a.rt 46 oit'lever 36, which under impulse of spring 38 will. ride up upon the beveled surface ll oi? the latch 35 so that the jaw will open releasing arm panied by a jerk or jar, causing the parts to shake and vibrate. With my attachment arm ,30 upon returning is caught by latch 35 positively preventing any rebound of the wing l3, most of the force of the impact being taken up by the spring 34. As this wing isioperated through'the foot treadle 11, it likewise absolutely prevents this back lash from again accidentally tripping the foot lever 11. Just as the foot treadle reaches its uppegi'niost position. and after the shock of the returning wing has subsided, the rod 42 W ll r un v ba 3% o that la i can engage the upper edge of one side 46 of ley'ferElG. In this position, Figvfi it is ready to unlock arm as another cycle oi move- It will thus be seen that the vibration of the guard this end oi its cycle of movement is absorbed or controlled by my device. r

I have described a preferred form of my invention in which a positive lock holds the wing 13 against backlash and undue vibrations, and which prevents accidental movement of the foot lever, but it is obvious that any device which would deaden the shock 02? the return movement would be withinthe scope of my invention. The vibration and shock could be cushioned by a weight or by a pneumatic device, for either of these would prevent the rebound of the guard. I prefer, however the machine which I have described, as it both absorbs theshojch of the rapidly moving guard and positively locks 1t 1n place.

Havmg thus described ru v invention what I claim as new and (les to secure by Letters Patent is r 1. In a safety guard for punch presses, the combination with a frame, a bed. a ram movable on the frame and actuating mechanism for the ram with a safety guard adapted to cross the bed thereby removing an oper to bend f om ben a h th am before t e same has d scended, a v r ion (30ntroller mounted on the frame, which will cooperate with the guard upon the completion of its mo ement.

2. In a saucy novice for punch presses, the combination with a pres comprising a frame, a bed, a ram movable over the bed, and means for actuating the ram, with a press guard adapted to cooperate with the ram moving" means to swing: across the bed, and a vibration controlling mechanism mounted on the frame adapted to cooperate with the press guard when the same is at rest.

3. In a safety device for punch presses, the combination of a press compr a frame, a bed, and a rain movable to and from the bed, with a safety guard adapted to cross the bed, mechanism for operating the ram, means for operating the guard, and a shock absorbing mechanism adapted to receive the impact of the safety guard as it comes to rest after an actuation comprising a spring jaw, a trippin (lBVlCe for the ram and for the guard operating mechanisms, said tripping means being adapter to render the spring momentarilyv inoperati-ve so that the guard and then the ram can be operated.

4. In a safety device for punch presses, the combination of a press comprising-a frame. a bed, and a ram movable to and from the bed, with a safety guard adapted to cross the bed, mechanism for ooerating the ram, means for operating the guard, and a shock absorbingmechanism adapt Z to receive the impact of the safe card as it comes to rest after an actuation compris ing a yielding spring tensioned j aw having a cam surface on one end, a lever for contactinp; with the cam and rendering the jaw inoperative, and a tripping device for the guard and the ramoperating mechanisms, this tripping mechanism also operating the cam contacting); lever so that when actuated the jaw will be rendered inoperative, the safety guard actuated, and the ram clutch tripped, all in the order given.

5. In a safety device for punch presses, the combination of a punch press. comprisa frame, a ram, and a bed with means for moving the ram, a clutch for operating A- rain movi mecha ism, ,nd a lever for operating the h, a safety guard i to the frame oted to swing; across the bed and back at each actuation of the ram, moving means for the guard, actuated indepei'idently of the ram moving mechanism through the lever which trips the ram clutch, a shock absorber on the frame consisting of a spring latch, the spring jaw of the latch adapted to first receive the s-ahoclc from and then restrict the movement of the guard, and means operated by the clutch operating lever for momentarily rendering the spring jaw inoperative before an actuation of the ram and guard.

6. In a safety device for punch. presses, the combination with a machine having a frame, a bed and movable parts operable over the bed, of means for actuating the movable parts to cause them to perform a cycle of operations, a guard adapted to cross the bed and return at each cycle of operations, means for moving the guard. and means for definitely retaining the guard in position after a cycle of ope 'ations is cons plete, thus preventing the guard momentum from vibrating; andaccidentally actuating the movable parts which operate over the bed through the means used for moving the guard. 80

7. In a safety guard for punch. presses, the combination with a machine having a frame, a bed and a ram mounted over the bed, of a safety guard adapted to move to and from an operative position across the bed, means for actuating the ram and means for actuating; the guard, both of said means being; actuated by common controlling member, and a devi e for limiting the movements of the safety guard as it moves to its inoperative position after an actuation, said device thus preventing the safety guard from accidentally operating; the ram through the common controlling men 79?. as the guard moves from its operative position across the bed.

8. in a press, a die, to which work is fed through apath, mechanism for movii'ig said die, a continual y rotating member, a clutch whiolii, when tripped, connects said member to Swi l mechanism for can 'ua cycle of operation of said. die. tripp devices for said clutch, a guard system including connections with said tripping devices and also including: a guard member normally out of said path but movable, in timed relation to said cycle, across said path and movable finally back to said normal position, and a safety element cu t: if. r and induci q its said moves back ac dental tripping of said match by reamion of said guard system on said tripping devices is prevented. V

Signed at R()Ul1QSlJB!J,.NGW York, this 11th day of September 1919.

EDMOND Dr; lllAlEClilllt. 

